Real-Time Ultrasound/MRI Fusion for Suprasacral Parallel Shift Approach to Lumbosacral Plexus Blockade and Analysis of Injectate Spread: An Exploratory Randomized Controlled Trial

Abstract

Fused real-time ultrasound and magnetic resonance imaging (MRI) may be used to improve the accuracy of advanced image guided procedures. However, its use in regional anesthesia is practically nonexistent. In this randomized controlled crossover trial, we aim to explore effectiveness, procedure-related outcomes, injectate spread analyzed by MRI, and safety of ultrasound/MRI fusion versus ultrasound guided Suprasacral Parallel Shift (SSPS) technique for lumbosacral plexus blockade. Twenty-six healthy subjects aged 21–36 years received two SSPS blocks (20 mL 2% lidocaine-epinephrine [1 : 200,000] added 1 mL diluted contrast) guided by ultrasound/MRI fusion versus ultrasound. Number (proportion) of subjects with motor blockade of the femoral and obturator nerves and the lumbosacral trunk was equal (ultrasound/MRI, 23/26 [88%]; ultrasound, 23/26 [88%]; p = 1.00). Median (interquartile range) preparation and procedure times (s) were longer for the ultrasound/MRI fusion guided technique (686 [552–1023] versus 196 [167–228], p < 0.001 and 333 [254–439] versus 216 [176–294], p = 0.001). Both techniques produced perineural spread and corresponding sensory analgesia from L2 to S1. Epidural spread and lidocaine pharmacokinetics were similar. Different compartmentalized patterns of injectate spread were observed. Ultrasound/MRI fusion guided SSPS was equally effective and safe but required prolonged time, compared to ultrasound guided SSPS. This trial is registered with EudraCT (2013-004013-41) and ClinicalTrials.gov (NCT02593370).

Depth of cervical plexus block and phrenic nerve blockade: a randomized trial

“…Strid et al used Dotarem to investigate local anesthetic spread and seemed to confirm diffusion of Dotarem through membranous fasciae, even into the epidural space. 17 Dotarem possesses an essentially neutral pH (6)(7)(8) in a water-based solution, therefore not interfering with ropivacaine's capability to diffuse through lipophile membranes. We are confident that this study adds substantial knowledge concerning the spread of local anesthetic solutions, be it by hydrostatic pressure or diffusion through extracellular space.…”

A lateral approach to ultrasound‐guided sacral plexus block in the supine position

“…Ultrasound‐guided sacral plexus block can be used to provide anaesthesia and analgesia for hip surgery. Recently, three methods of ultrasound‐guided sacral plexus block have been reported: a short‐axis method ; long‐axis method ; and a suprasacral parallel shift approach to lumbosacral plexus blockade . These require the patients to be in either a lateral decubitus or a prone position, which can be difficult to achieve for hip trauma patients.…”

Development of Guidance Techniques for Regional Anesthesia: Past, Present and Future

“…The UCOT (image fusion) has been applied in the field of regional anesthesia. Strid et al 61 conducted the first randomized controlled trial of ultrasound/MRI fusion for lumbosacral plexus block and confirmed that ultrasound/MRI fusion technology was effective and safe. However, compared with ultrasonic guidance, it requires a longer preparation process.…”